M fischeb



(No Model.)

' W. FISCHER.

PIANO.

Patented Dec. 9. 1884.

UNITED Stars.

\VILHELM FISCHER,

PIANO.

.JPECHICATION forming part of Letters Patent No,

25, 1882, No. 39,27 1 and No. 1,755.

To all whom it may concern.-

Be it known that LWILHELM Fisoiinn, residing in Dresden, Saxony, German Empire, have invented certain new and useful Improvements in Pianos, Letters Patent have been obtained in Great: Britain October 6,1881, No. 4,311; Belgium October 6, 1881, No. 55,895; France October 6, 1881., No. 145,177; Austria-Hi1ngary, No. 39,274 and No. 1,755, January 25, 1882, and Germany October 6, 1881, No. 18,590,) of which the following is a specification.

My invention relates to pianos in which the tones are produced by forks of metal or other suitable material and similar to tuning-forks; and the improvements consist in the particular mode of connecting the forks to the soundingboard of the instrument; in the meansemployed for rendering their sound more pure, and in a device by which the strength of the sounds may be modulated at the will of the player.

011 the annexed sheet of drawings, Figure 1 represents a sectional viewof a piano comprising a part of the improvements. Fig. 2 is a sectional end view combined therewith. Fig. 3 shows the forks and their attachment in plan, and t the means employed for ii'nproving the sound of the forks.

The sounding-forks hitherto used in pianos have always been rigidly fixed within tne same, or attached collectively to a bar which is so cured to the sounding-board. 'When a fork thus arranged is struck by a han'nner of the piano mechanism, the percussion thus caused is always more or less audible, in 0011801 uence whereof the musical effect 01' the instrument is considerably impaired. For the purpose of remedying this deficiency, l1 makethc connection between the forks a and the soundingboard (1 by means ofjoints or hinges 1.7, as shown by Figs. 1 and 8. The fork is screwed with its stem to the part a of the hinge, while the other hinge part, 8, is fixed to the bar '1), attached by means of the stays c, or in other suitable manner,to the souiuling-board d.

In order to keep the forks in their horizontal position, a ledge, r,

the hinge parts a are supported by. which is covered on its upper sur- OF DBESDEA SAXONY, (lJlRMANY.

in Germany October 0, 1881, No. 18,590, and in Austriallungary January (for all or a part of which 2 of the forks and of parts arena @rrtea.

309,138, dated December 9,1884.

England October I"), 1881, No. 1,311; in Belgium October (3, 1881,

er-and a screw, q, provided with a knob, which is also covered with felt or leather, and which pre ses gently from above on each of the parts 11.

1 Instead of the screw (pa spring or a weight t maybe used. Thisarrangement,which allows t the fork to yield toa certain amount when it is l struck by the hammer c, has proved very y efticient, not only for preventing the blow of the hammer from being heard, but also for t rendering the sound more sonorous.

1 According to the experiments hitherto made, it is advantageous in respect to the t quality of the sound to place the forks pert pendieular to the sounding-board. latter is horizontal, theforks should therefore 1 have a perpendicularposition. The arrange ment of the forks parallel or at a sharp angle to the sounding-board is. however, cludcd.

The part a of the hinge may be made in one piece with the stem of the fork; but I prefer to construct bothhinge parts 8 and a of wood, and to attach the fork to the part a, as shown 1 in the drawings. Instead of the hinge 7. however, a springing connection between the parts sand a may be employed, and in this case,

not ex- 1 especially when the forksare in a perpendicular 1 position, the supports r and 1 may be omitted. t The second partof the invention consists in i the means for improving the purity of sound t of the fork. \Vhen a tuning-fork is made to l vibrate, the sound produced is not a simple I musical note, but a combination of the fundamental note of the fork and of a higher note, called in acoustics the harmonic, which latter increases in strength as the pitch of the fork becomes lower, and which in the bassforks even predominates over the'fundamental This higher note, which impairs the purity of the sound, may be suppressed. by placing a ring or band, 0, made of or lined wit h an elastic 1naterial,tightly around one of the prongs of the fork at a certain point of the same. 1t has been found that a ring of india-rubber with a piece of felt, 1), put unlderneath, is particularly suitable for this purpose. The true position of the said ring must note.

face with a soft 111atcrialsuch as felt or leath sci Set be determined by experiment, but generally it will have to be located at about one-third of the length of the prong from its point of union with the other prong.-

lhe third part of the invention relates to the modulation of the strength of the notes. As means therefor, I use resonance-tubes i, Figs. 1 and 2, together with a slide, m, by which their sound-holes Z, Fig. 1, may simultaneously be closed more or less. Resonancetubes have been applied already by others for i the purpose of increasing the intensity of the l sound produced by the forks. The said tubes, which must betuned in unison withthe forks, I are fixed above or in general close to the same. l V hen the distance between the tubes and the 1 forks renders it necessary, their sound-holes 7, which are opposite to the ends ofthe forks, have I to be provided with tubular attachments Z. The slide m, consisting of a thin bar of wood I or metal, or of other suitable material, is so connected with a pedal that it may be brought before the sound-holes or their attachments or I shifted away from them at the will of the] player. Considering that the vibrations of} the air in the resonance-tubes are caused by l the transmission of the vibrations of the forks through the sound-holes, it is evident that the former will become fainter the more the free area of the sound-holes is reduced. The arl rangement thus affords the means not only of producing sounds of greater or less strength, i but also of increasing or diminishing the strength of any note or chord after the forks have been put in vibration.

= any other The hammer mechanism shown in the drawings presents no new features, and does not therefore require any description. Besides, mechanism of this kind may be used.

Bya suitable arrangement of forks tuned in the octave of those to be struck by the hammers it is possible to obtain in the described instrument an eflcct similar to that of the aliquot system in stringed pianos.

I claim as my invention 1. In pianos in which forks are employed for producing sounds, the combination, with the sounding-board (Z, of a series of forks, a, each fork being attached to the sounding-board by an individual flexible connection, substantially as and for the purposes hercinbe'forc set forth.

2. In combination with the forks a,attaclied to the sounding-board (Z by a flexible connection, the supports hereinbeforc specified.

3. In combination with a sounding-fork, an elastic ring or band, 0. placed tightly around one of its prongs for the purpose of suppressing the harmonic of the fundamental note, as described.

In testimony whereof I. have signed my name to this specification in the presence oftwo subscribing witnesses.

\V I LHE LM Fl SOIIER.

Witnesses:

PAUL Dnnokniimymz, CARL Son'noDnn,

Bot/1. of Dresden.

and q, substantially as 

